JP4891711B2 - Temperature expansion valve - Google Patents

Description

The present invention relates to a temperature expansion valve, and more particularly to a temperature expansion valve constituting a refrigeration cycle of a vehicle air conditioner.

  Various types of temperature expansion valves used in the refrigeration cycle are known. This type of temperature expansion valve has a high-pressure refrigerant passage through which refrigerant flowing into the evaporator flows and a low-pressure refrigerant passage through which refrigerant flowing out of the evaporator flows, and a valve hole is provided in the middle of the high-pressure refrigerant passage. A valve body that contacts and separates the valve hole of the valve body and changes the opening of the valve hole, a diaphragm that drives the valve body via an operating rod to control the operation of the valve body, and the valve body It has an airtight chamber filled with temperature sensing gas partitioned by a diaphragm and a pressure equalizing chamber communicating with the low-pressure refrigerant passage, and is arranged in the upper opening of the valve body so as to sense the temperature of the gas-phase refrigerant in the valve body And a plug for sealing the outer wall hole while maintaining the state when the filling is completed after filling the temperature-sensitive gas into the airtight chamber from the hole formed in the outer wall constituting the element part. It is the structure which comprises (for example, patent document 1).

In the above-mentioned temperature type expansion valve, in order to enclose the hole formed in the outer wall with a plug, it is important that the plug is securely welded to the hole and that the welding strength between the plug and the hole is sufficient. is there.
In this regard, in the conventional temperature expansion valve, the welding of the plug body is contacted at the tapered surface portion with respect to the hole of the outer wall and projection welding is performed, and the length of this welding is limited, and projection welding is further performed. It has been proposed to cover the periphery formed around the surface with a corrosion inhibitor so that water does not stay (for example, Patent Document 1).

Further, in the conventional temperature type expansion valve, a flange that is continuous with the spherical surface portion of the plug body is formed by projection welding the edge contact portion with the edge of the hole formed in the outer wall using the spherical plug body. It has also been proposed to perform two-stage welding in which the part is soldered (Patent Document 2).
Furthermore, it has also been proposed that the plug body may be inclined when welding with the hole using the spherical plug body (Patent Document 3).
JP-A-8-226567 JP-A-6-185833 JP 2001-116401 A

  However, in the conventional temperature expansion valve, a protrusion and a conical portion are formed on the plug body to form a tapered surface portion to be welded, and the outer wall hole is inclined obliquely downward toward the center. This requires the complexity of the processing step of forming the film.

  Further, in the conventional temperature expansion valve that performs the two-stage welding, it is difficult to perform projection welding over the entire circumference of the spherical surface portion, and there is a possibility that the strength becomes insufficient.

For these reasons, the conventional temperature expansion valve may cause a problem that it is difficult to obtain a stable welded state of both the hole and the plug formed in the outer wall. Further, in the conventional temperature expansion valve, there is a possibility that the reliability of welding between the hole of the outer wall and the plug is insufficient.
Further, when the spherical plug body is inclined and welding is performed, contact with the holes becomes non-uniform, which may cause poor welding.

  The problem to be solved by the present invention is to realize welding of a hole of an outer wall that forms a temperature sensing chamber and a plug body that seals a temperature-sensitive gas injected from the hole in a stable welding state. It is an object to provide a temperature expansion valve that further improves reliability by preventing welding failure by further reliably performing welding.

In order to solve the above problems, the present invention includes a plug for sealing a hole formed in the outer wall of the hermetic chamber for sealing a predetermined refrigerant in the hermetic chamber formed by a diaphragm that drives the valve body. In the temperature type expansion valve, a recess is formed in the outer wall, the recess is formed in a step shape inward, and a flat bottom is provided, and the hole is provided in the flat bottom. The plug has a protrusion on the lower surface, the protrusion contacts the flat bottom of the recess, and the plug seals the hole by resistance welding. A valve is provided.

Temperature expansion valve of the present invention, preferably the the stopper to form a convex portion, the said convex portion together with the protrusions around the convex portion is configured inserted into said hole of said recess Is done.

Also, the protrusion is formed with a top flat surface, it is preferable that the top flat surface is welded in contact plane equivalent to the planar bottom portion of the recess.

It is preferable that the protruding portion is formed to have an edge portion, and the edge portion is abutted against and contacted with the planar bottom portion of the recess .

The plug is preferably arranged at a distance to the side surface of said recess and the plug body.

  The gap is preferably filled with a corrosion inhibitor.

According to such a temperature expansion valve, plug body is formed in a disk shape, has a protrusion formed on the lower surface thereof, the projections on the planar bottom of the recess person Since it is possible to perform welding by concentrating the energy of resistance welding to the protrusions in electrical resistance welding, not only can energy saving be achieved, but the plug body can easily ensure stable contact. Therefore, it is possible to avoid the occurrence of insufficient strength in the resistance welding, and to improve the reliability .

  Further, by forming a convex portion on the plug body and providing the projection around the convex portion, the convex portion can be inserted into a hole formed in the recess, so that the plug body Can act as a guide with the convex portion. As a result, in resistance welding, the plug body can be welded to be easily and stably placed in contact with the recess.

Furthermore, since the protrusion is formed with a top flat surface, since it is arranged by the planar bottom and a plane abutment of said recess, it is not that the plug body is tilted . As a result, poor welding can be avoided by reliable welding based on a stable arrangement.

Furthermore, since the plug body has a protrusion formed in an edge shape, the edge portion allows the plug body to abut against the planar bottom portion of the recess. As a result, the plug body can be fixed to the recess very stably, and it becomes possible to improve the concentration of energy by resistance welding and to perform the welding of both.

  In addition, the plug body has a hole in a bottom portion in a recess formed in the outer wall, and a projection portion of the plug body arranged in the recess is in contact with an outer wall surface of the bottom portion of the recess. Thus, the welding of both can be performed reliably, so that welding failure can be reliably prevented.

  Furthermore, when the plug body is disposed in the recess, the circumferential surface of the recess and the side surface of the plug body have an interval, so that electrical conduction occurs between them. Since the plug body can be easily and stably secured, it is possible to provide a temperature expansion valve that can be reliably welded and improved in reliability without insufficient strength.

  Further, according to this temperature expansion valve, the gap between the plug body and the recess can be filled with the corrosion inhibitor, so that water does not stay in the gap and the occurrence of corrosion is prevented. be able to.

According to the temperature expansion valve of the present invention, since the plug body can be disposed on the flat bottom portion in the recess by forming a protrusion on the lower surface, the plug body can easily ensure stable contact. Therefore, it is possible to avoid the occurrence of insufficient strength in the resistance welding and improve the reliability.

  Further, according to the temperature expansion valve of the present invention, since the plug body can be easily disposed with a gap in a recess formed in the outer wall of the power element, the plug body and the outer wall can be disposed. It is possible to perform resistance welding by avoiding electrical continuity between them, and to prevent poor welding and to provide a temperature expansion valve that does not have insufficient strength.

  Hereinafter, an embodiment of a temperature expansion valve according to the present invention will be described with reference to FIGS. 1, 2, and 3. FIG.

  As shown in FIG. 1, a valve body 1 of a temperature expansion valve arranged in a refrigeration cycle of a vehicle air conditioner is supplied from a high-pressure refrigerant flow path 2 through which liquid refrigerant supplied to the evaporator flows and the evaporator. The low-pressure refrigerant flow path 3 is provided. A small diameter valve hole 4 is provided in the middle of the high-pressure refrigerant flow path 2. Then, the liquid refrigerant flowing from the liquid receiver in FIG. 1 to the high-pressure refrigerant flow path 2 is adiabatically expanded by passing through the small-diameter valve hole 4. A valve seat is formed on the refrigerant inflow side of the valve hole 4, and a ball valve 5 is provided on the valve seat as a valve body so as to be contactable and separable so that the opening area of the valve hole 4 can be changed. The ball valve 5 is supported by a valve body receiving member 7 and is biased in a direction in which the ball valve 5 is pressed against the valve seat by a coil spring 9 interposed between the valve body receiving member 7 and the adjusting nut 8. Yes. Reference numeral 21 denotes an evaporator-side outlet of the high-pressure refrigerant flow path 2.

  An element portion 10 that detects the gas-phase refrigerant temperature is disposed at the upper end portion of the valve body 1. In the element portion 10, a disc-shaped lower wall 18 is fixed to the upper end portion of the valve body 1 via an O-ring 17. The outer wall 14 is placed on a circumferential surface formed on the outer periphery of the lower wall 18 so as to face the disk-shaped lower wall 18 and is welded by a welding portion 19. A diaphragm 6 is interposed in the internal space between the lower wall 18 and the outer wall 14, an airtight chamber 12 is formed in the space between the outer wall 14 and the diaphragm 6, and a lower space 13 is formed between the lower wall 18 and the diaphragm 6. Has been. In the lower space 13, a receiving member 101 is placed on the lower wall 18, and the receiving member 101 abuts against the diaphragm 6 and serves as a stopper portion for the diaphragm 6.

  The upper end of the operating rod 102 is inserted into the receiving member 101, and the lower end of the operating rod 102 is in contact with the ball valve 5 to press the ball valve 5. The operating rod 102 passes through the hole 11 of the valve body 1 and is supported by an O-ring 110 and a fixing ring 111 provided in the hole 11.

As shown in FIG. 2, the outer wall 14 is made of a metal, for example, stainless steel, and is formed in a disk shape, and the central portion 141 is formed to rise upward from the rising portion 142 on the outer side to the central portion. A flat portion 143 is provided.
In the flat part 143 of the outer wall 14, a recess 15 is formed around the center, and the recess 15 is formed in a step shape inwardly and is provided with a flat bottom part 151. A hole 152 communicating with the hermetic chamber 12 is provided in the center portion further downward from the planar bottom portion 151.

  A cylindrical plug 16 having a disk portion 16g made of metal, for example, stainless steel, is fitted into the hole 152 of the recess 15. As shown in FIGS. 3 and 4, the cylindrical plug body 16 has a step 16 c formed on the lower surface 16 e and is provided with a small-diameter cylindrical protrusion 16 a. A columnar convex portion 16b having a smaller diameter is provided so as to be connected to the top flat surface 16d below the protruding portion 16a. As shown in FIG. 4, the protruding portion 16 a and the protruding portion 16 b protrude in a columnar shape concentrically with the plug body 16.

According to the plug body 16, the convex portion 16 b of the plug body 16 is inserted into the hole 152 formed in the bottom portion 151 of the recess 15 of the outer wall 14, so that the plug body 16 is disposed in the recess 15. The top flat surface 16d of the step portion 16c abuts on the planar bottom 151 of the recess 15 of the outer wall 14 and abuts and engages the plug body 16 with the outer wall 14.

Therefore, when the plug body 16 is inserted into the recess 15, it is stably and reliably engaged with the outer wall 14 without being inclined. As a result, when the resistance welding of the outer wall 14 and the plug body 16 is performed, the energy can be concentrated and the welding can be carried out locally, so that it is possible to ensure that the both are welded. The 14 holes 152 can be sealed by preventing the possibility of poor welding.
4 shows a projection 16b formed on the lower surface 16e, a projection 16a formed on the periphery thereof, and a stepped portion in order to contact and engage the disc-shaped plug 16 shown in FIG. 3 with the outer wall 14. It is a bottom view which shows 16c.

FIG. 5 is a cross-sectional view of the plug 16 showing the main part of another embodiment of the present invention.
As shown in FIG. 5, a cylindrical plug body 16 having a disk portion 16g made of metal, for example, stainless steel, is fitted into the hole 152 of the recess 15 shown in FIG. The cylindrical plug 16 has a conical protrusion 16a formed on the lower surface 16e. The projecting portion 16a is connected to the lower surface 16e of the plug body 16 in an annular shape downward from the central portion of the plug body 16, and is a small-diameter columnar convex portion 16b concentrically with the plug body 16 and projecting downward in a cylindrical shape. Is provided integrally with the plug body 16 in an annular shape so as to have an edge portion 16f at the tip thereof.
The convex portion 16b and the protruding portion 16a project downward in a concentric manner with the plug body 16. In addition, you may form and provide the convex part 16b and the projection part 16a separately from the plug body 16. As shown in FIG.

According to the plug body 16, the convex portion 16 b of the plug body 16 is inserted into the hole 152 formed in the bottom portion 151 of the recess 15 of the outer wall 14, so that the plug body 16 is disposed in the recess 15. The edge portion 16f is abutted against the planar bottom portion 151 formed on the flat surface of the recess 15 of the outer wall 14 and acts as a guiding guide, so that the plug 16 is brought into contact with and engaged with the outer wall 14.

Therefore, when the plug body 16 is inserted into the recess 15 and welded, the plug body 16 is stably and firmly fixed and engaged with the outer wall 14. As a result, when the resistance welding of the outer wall 14 and the plug body 16 is performed, the energy can be concentrated and the welding can be carried out locally, so that it is possible to ensure that the both are welded. It is possible to seal the outer wall hole 152 by preventing the possibility of poor welding in the fourteen hole 152.
FIG. 6 is a bottom view showing a protrusion 16b formed on the lower surface 16e, a protrusion 16a formed on the periphery thereof, and an edge 16f in order to fix the disc-shaped plug 16 shown in FIG. 5 to the outer wall 14. FIG.

  Furthermore, in the embodiment shown in FIGS. 1 and 2 in the present invention, when the plug body 16 shown in FIG. 3 or 5 is disposed in the recess 15 formed in the outer wall 14, the plug body 16 is As shown in FIG. 2, it is provided so as to be arranged with a recess 15 and a gap L.

That is, as shown in FIG. 7, the plug body 16 is formed to have the projections 16a and the projections 16b shown in FIGS. 3 and 4, so that the disk portion 16g serving as the large-diameter portion where these are formed is formed. The side surface 16 i is disposed with a gap L between the side surface 16 i and the inner surface 153 in the recess 15.
In this arrangement, the plug body 16 is provided with the gap L such that the diameter of the disk portion 16g, which is a large diameter portion, is 5.75 mm, for example, and the diameter of the recess is 6.2 mm, for example.

According to such an embodiment, the plug body 16 is arranged with the recess 15 of the outer wall 14 and the gap L. Therefore, when performing resistance welding in the contact between the projection 16a and the bottom 151, the plug body It is possible to avoid the occurrence of electrical continuity between the side surface 16i and the inner surface of the recess 15.
Thereby, it is possible to prevent the occurrence of poor welding due to the loss of current concentration when welding the projecting portion 16a, the recess 15 and the bottom surface 151 with each other.

  As a result, the sealing of the plug body 16 and the outer wall 14 by welding can be performed more reliably, the occurrence of poor welding due to the sealing of the plug body can be prevented, and the temperature expansion further improving the reliability. A valve can be provided.

Furthermore, in the embodiment of the present invention, the gap L can be filled with a corrosion inhibitor, for example, a resin adhesive S.
Figure 8 shows a state in which the plug body 16 shown in FIG. 7 when arranged in the recess 15, the plug 16 and recess 15 adhesive made of resin into the gap L held between S is injected filled ing.

  With such a configuration, water does not enter and stay in the gap L, and corrosion can be prevented.

In the above description of the present invention, the plug body shown in FIG. 3 has been described. However, the present invention also has a gap between the side surface 16i and the inner surface 153 of the recess 15 in the plug body shown in FIG. And can be disposed in the recess , and the gap can be filled with an adhesive.

It is a longitudinal cross-sectional front view which shows 1st Embodiment of the temperature expansion valve by this invention. It is a longitudinal cross-sectional view which expands and shows the principal part of embodiment of FIG. It is a longitudinal cross-sectional view which expands and shows the structure of the plug body of embodiment of FIG. It is a top view of the stopper of FIG. It is a longitudinal cross-sectional view which expands and shows the structure of the other plug body of embodiment of FIG. It is a top view of the stopper of FIG. It is a longitudinal cross-sectional view which shows arrangement | positioning of the plug in the principal part of embodiment of FIG. It is a longitudinal cross-sectional view which shows the state which filled the corrosion inhibitor in the gap | interval L shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Valve body 5 Valve body 6 Diaphragm 12 Airtight chamber 14 Outer wall 15 Recess 152 Hole 16 Plug body 16a Protrusion part 16b Protrusion part 16c Step part 16d Top part flat surface 16e Lower surface 16i Side surface L Gap S Corrosion inhibitor

Claims (5)

In the thermal expansion valve comprising a plug for sealing a hole formed in the outer wall of the hermetic chamber for sealing a predetermined refrigerant in the hermetic chamber formed by a diaphragm for driving the valve body, the outer wall is recessed. The recess is formed in a stepped shape inward to provide a flat bottom, the hole is provided in the flat bottom, and the plug has a protrusion on the lower surface. A temperature expansion valve, wherein the protrusion abuts against the planar bottom of the recess, and the plug seals the hole by resistance welding. Temperature expansion valve according to claim 1 wherein the plug body to form the convex portion, the convex portion with the protrusion on the periphery of the convex portion is configured to be inserted into said hole of said recess. The protrusion is formed with a top flat surface, the temperature of claim 1 or 2 wherein the top flat surface, characterized in that it is welded in contact plane equivalent to the planar bottom portion of the recess Expansion valve. The protrusion is formed with an edge portion, the temperature expansion valve according to claim 1 or 2 wherein the edge portion and wherein the abutting said abutted against the flat bottom of the recess. The plug, the temperature expansion valve according to any one of claims 1 to 4, characterized in that it is arranged at a distance to the side surface of said recess and the plug body.

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